Adjusting and safety means for the hammer of the bobbin changer in weaving looms



March 3, 1959 PlCANOL 2,875,791

ADJUSTING AND SAFETY MEANS FOR THE HAMMER OF THE BOBBIN CHANGER IN WEAVING LOOMS Filed NOV. 1, 1956 J. Pipanol, MVt-WTO/P United States Patent mfnUsTuso AND SAFETY MEANS-FOR THE MEO'R gr THE sonsm CHANGER IN WEAVIYG L M Jaime Picanol, Ziliebeke-lez-Ypres, Belgium Application November 1, 1956, Serial No. 619,790

Claims priority, application Belgium December 17, 1955 7 Claims. cl. 139-243 In weaving looms having a bobbin change-over device it is of essential importance to dispose of means for ensuring a correct change-over of the bobbins, i. e., more particularly for ensuring a rigorous control of the movements of the hammer or pusher operating at each bobbin change. This safety is the more desirable, but also the more diflicult to realize, the higher is the heating rate of the loom. In fact, already in a loom working at a normal speed the time available for the change is only of the order of an, of a second, so that very fast movements are required. The hammer, which is 'the most essential element of the bobbin changer, has certain dimensions and a certain weight so that it appears rather difficult to arrest said hammer exactly in the right "position at the end of its stfoke. However, if the hammer tends toovershoot the normal end position of its stroke, the use of a stroke-limiting stop element would entail the risk of damaging either said stop element or the hammer itself, due to the impact of the hammer when it strikes the stop. On the other hand an unchecked overshoot is highly undesirable, as the impact would then be transmitted to the filled bobbin and simultaneously to the empty bobbin underlying said filled bobbin. In the case of insuflicient displacement of the hammer, i. e., if the hammer would never quite reach the required end position, there would be a risk that one or the other of said bobbins, or both, would get stuck half way, and all these contingencies are extremely detrimental for the materials. Finally it must be noted, that the use of elastic means, particularly of resilient end stops cannot practically be considered, in view of the dimensions of such means and the little space available.

An important step therefore would be to provide the bobbin changer, more particularly the hammer of the bobbin changer, with limiting means capable of ensuring rigid control of the length of the stroke without resorting to a dangerous reduction of the kinetic energy of the hammer, and also without causing a recoil of the latter.

The invention contemplates such means, which is extremely simple as well as robust, and adapted to enable the hammer to operate in a perfectly correct manner.

This means according to the invention comprises a toggle joint or such like system of endwise jointed elements connecting the hammer with a relatively fixed support so as to limit the movement of said hammer at the end of its stroke by the alignment of the hinges between the parts of said toggle joint or system of jointed elements. Apart from the striking simplicity of this device it also provides a means for very precise and easy adjustment. This means is related to the possibiilty of shifting the pivoting axis of the last link of said system of jointed elements, e. g., by means of an eccentric device, whereby the position of said pivoting axis may be modified relatively to the remaining pivots of the toggle joint, and consequently also the alignment conditions of said pivots, by which the end of the hammer stroke is determined.

The various characteristic features of the invention will be brought out more clearly by an example described here- 2,875,?91 i atented Mar. 3, 1959 wherein:

Figure 1 is a somewhat diagrammatic representation of a bobbin changer for a weaving loom, showing the relative position of the adjusting and safety device of the invention therein;

Figure 2 is a schematic representation of the hammer equipped with the adjusting and safety device of the invention, showing the essential parts of the hammer, while the latter is at rest;

t Figure 3 is a similar representation to Figure 2, showing the hammer in its working position;

Figure 4 is a front view of the device for shifting the pivoting axis of the last link.

The hammer 1 and the driving bar 2 of the bobbin changer, the pivot 3 as well as the appurtenances with which said elements are normally equipped, may be of any kind similar to those generally used.

However in View of the application of the arrangement accordingto the invention, said hammer 1 is formed, at

its rear side, with an additional arm 4, said arm being connected with a rocking lever 5, e. g., by means of a pair of links 6-7 pivoted as at 89. The rocking lever 5 pivots on a shaft 10 which is mounted in an eccentric support enabling to shift or to adjust the position of said shaft 10 by simply rotating said eccentric support.

The whole device is urged back into the rest position by a spring suchas schematically indicated at 11.

In operation, when the hammer 1 is actuated in the usual way by the fact that the driving bar 2, under the control of the feeler, is placed in the path of the batten symbolised as at 12, said hammer exerts a pull on the rocking lever 5, while causing the pivot axes 8 and 9 to shift until the latter are in alignment with the axis of the shaft 10, whereby with almost mathematical precision the end of the hammer stroke is determined. Apart from this precise limitation of the hammers course, it is also achieved, by the favourable cooperation between the hammer 1, the links 67 and the rocking lever 5, that said hammer, when arrested at the end of its stroke, suffers practically no recoil from said limiting elements.

The limit of the hammer stroke may be adjusted with great precision, by modifying the position of the shaft. 10 through simple rotation of the eccentric support of said shaft. Such modification causes a corresponding change of the course of the hammer 1 as limited by the aligned condition of the axes 8-9-10.

The safety of the hammer operation is principally due to the fact that a considerable portion of the kinetic energy of the hammer is absorbed by the setting in motion of the rocking lever 5, so that at the end of the stroke of the hammer, the latter will have spent most of its energy; the necessity of providing said hammer with springs or shock absorbers, with all the difficulties connected therewith, is thus obviated.

It will be understood that various changes of the shape and the dimensions of the different elements as described above may be resorted to, in order to suit them to any particular kind of bobbin change-over mechanism.

What I claim is:

1. In a bobbin changing mechanism for weaving looms comprising means for pushing a new bobbin into the shuttle if the bobbin contained therein is empty, a support mounted on a fixed part of the frame of said loom, a plurality of link elements and hinges interconnecting endwise said link elements, said link elements interconnecting said pushing means with said support and adapted to limit the movement of said pushing means at the end of its stroke by the alignment of the hinges between the elements of said plurality of hinged elements.

2. In a bobbin changing mechanism for weaving looms comprising means for pushing a new bobbin into the shuttle if the bobbin contained therein is empty, a support mounted on a fixed part of the frame of said loom and a toggle joint interconnecting said pushing means with said support and having pivots joining parts of said toggle joint, said toggle joint being adapted to limit the movement of said pushing means at the end of its stroke by the alignment of the axes of said pivots.

3. In a bobbin changing mechanism for weaving looms comprising means for pushing a new bobbin into the shuttle if the bobbin contained therein is empty, a support mounted on a fixed part of the frame of said loom and a toggle joint interconnecting said pushing means with said support and having hinges, said hinges being so disposed as to be in a folded condition, when said pushing means is in its rest position, while extending along a straight line when said pushing means reaches the end of its stroke, thus arresting said pushing means in said end position.

4. In a bobbin changing mechanism for weaving looms comprising means for pushing a new bobbin into the shuttle if the bobbin contained therein is empty, a support mounted on a fixed part of the frame of said loom, a rocking lever rotatably mounted on said support and a link member pivoted on said pushing means and on said rocking lever, said rocking lever and said link member having their pivot axes so disposed that the latter are brought into alignment, when said pushing means reaches the end of its operating stroke, whereby said pushing means is arrested in said end position.

5. In a bobbin changing mechanism for weaving looms comprising means for pushing a new bobbin into the shuttle if the bobbin contained therein is empty, a support mounted on a fixed part of said loom, a rocking lever rotatably mounted on said support and a link member pivoted on said pushing means and on said rocking lever, the straight line connecting the pivot point of said rocking lever with the pivot between said rocking lever and said link member being substantially at right angles with the straight line connecting both pivots of said link member, when said pushing means is in its rest position, while the angle between both said straight lines widens to when said pushing means reaches the end of its stroke.

6. Bobbin changing mechanism for weaving looms as claimed in claim 4, in which said support is mounted on said fixed part of said loom so as to enable displacement of said support with respect to said loom in order to provide for adjustment of the end position of said pushing means.

7. Bobbin changing mechanism for weaving looms as claimed in claim 4, in which said support is rotatably mounted on said fixed part of said loom, the axis of rotation of said rocking lever on said rotatable support being disposed outside the axis of rotation of said support on said fixed part, in order to provide for adjustment of the position of said axis of rotation of said rocking lever.

References Cited in the fileof this patent UNITED STATES PATENTS 2,207,078 Stuer July 9, 1940 2,350,308 Burdett May 30, 1944 2,365,362 Stuer Dec. 19, 1944 

